Comments on Computation Including Latent Heat Effect for Laser Cladding Process

초록

Laser cladding process accompanies phase transformations from melting (on heating) through solidifying (on cooling) at the same time within a small material volume and to final solid phase. The phase transformations are not reversible, but an irreversible thermodynamic process; they accompany either absorption or release of thermal energy (referred to latent heat) during transformation. Yet, most analyses on materials processed by laser as a heat source have been performed on models of neglecting the latent heat in the process and those did not justify the simplification. With literatures on the laser material process, we have not placed an answer to how little the assumption affects on analyses. This led us to our current study; the effects of latent heat on thermo-mechanical anaysis. To this end, we developed a fairly accurate program accommodating an algorithm for enforcing the latent heat whenever neccessary and ran it combining with ABAQUS. The simulation techniques we used in this study were verified by directly comparing our prediction with experimental publications elsewhere; our numerical results agreed accurately with the experiments. On the effects of the latent heat, we performed two alternatives about considering the latent heat in analysis, and compared each other. As a result, we found that more accurate conclusions might come out when considering the latent heat in process analyses.